Piano string-plate.



G. A. HADDORFF.

PIANO STRING PLATE.

APPLIOATION FILED 11011.15, 1910.

1,032,895. v Patented J111y16,1912.

lfi'flzess'esx hrenzaz': E G CZ NW 0% g/QM; (w. W

COLUMBIA PLANOGRAPH 001, WASHINGTON, D. C.

UNITED STATES PATENT oEEIoE.

CHARLES A. HADDORFF, OF ROCKFORD, ILLINOIS, ASSIGNOR TO HADDORFF PIANO COMPANY, OF ROCKFORD, ILLINOIS, A CORPORATION OF ILLINOIS.

PIANO STRING-PLATE.

To all whom it may concern:

Be it known that I, CHARLES A. HAD- DORFF, a citizen of the United States, residing at Rockford, in the county of WVinnebago and State of Illinois, have invented certain new and useful Improvements in Piano String-Plates, of which the following is a specification.

The object of this invention is to so construct the plate of a piano that the tension of the strings on the pin plank will seat the plank firmly in contact with the plate and prevent its displacement, thereby preventing the slackening of the wires.

In the accompanying drawings, Figure 1 is a plan view of a portion of a plate. Fig. 2 is a section on dotted line a a Fig. 1.

The plate 1 is of the usual face outline, and is formed with a rib 2 on its rear face. The face 3 of this rib is located at an acute angle wit-h respect to the rear face 4 of the plate, which forms an under cut trough or channel.

The pin plank 5 is of a form to fit against the rear face 4 of the plate and against the face 3 of the rib 2 and screws 6 connect the plank and plate. Pins 7 are located in the pin plank in the usual manner. Strings 8 are connected to the pins in the usual manner. The pins and strings are located adjacent to the front face of the plate. The tension of the strings tends to hold the pin plank firmly seated in the trough or channel of which the rear face of the plate and the face 3 of the rib form the walls. As the edge of the pin plank that is seated in the trough or channel is closely fitted therein, there will be no movement of the pin plank under the tension of the strings.

Specification of Letters Patent.

Application filed November 15, 1910.

Patented July 16, 1912.

Serial No. 592,576.

Heretofore the face of the rib has been located at an obtuse angle wit-h respect to the rear face of the plate in order that in casting the plate, suflicient draft might be given to the rib. Then the pin plank was located in this connection with the rib, the tension of the strings on the pin plank caused the pin plank to recede from the rear face of the plate, consequently shortening the length of the strings which will place the strings out of tune. By my arrangement, the pin plank cannot yield, consequently the strings will stay in tune longer than heretofore.

I claim as my invention:

A piano plate having a face parallel to the main portion of the piano strings and provided with an outstanding rib having a rear face that extends from and is disposed at an acute angle to the said face of the piano plate and overhangs the same, a pin plank located against the said face of the piano plate and having an edge beveled to correspond to the overhanging face of the rib and bearing against the same, pins pass ing through the plate and entering the plank, and strings secured to the pins and having their main portions disposed transversely of the rib and parallel to the said face of the piano plate, said strings drawing the beveled edge of the plank firmly against the acute face of the rib.

In testimony whereof I have hereunto set my hand in presence of two subscribing Witnesses.

CHARLES A. HADDORFF. lVitnesses: R. O. BEHEL, E. D. E. N. BEHEL.

Copies of this patent may be obtainedfor five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

